Gun perforator



T. A. HUBER I 2,876,843

March 10,1959" GUN PERFORATOR Filed Aug. 23, 1954 4 Sheets-Sheet l 777e000/e 4. flab er INVENTOR.

March 10, 1959 T.- A. HUBER GUN PERFORATOR 4 Sheets-Sheet 2 Filed Aug. 23, 1954 Theodore A. Huber INVENTOR.

A T70R15) March 10, 1959 T. A. HUBER GUN PERFORAIQR 4 Sheets-Sheet 4 Filed Aug. 23, 1954 e A. Huber l ilmnv INVENTOR.

United States atent GUN PERFOR'ATOR' Theodore: A. Huber, Houston, Tern, assignor, by mesne assignments, to Jersey Production Research. Company, Tulsa, Okla, a corporation of Delaware Application August 23, 1954, Serial No. 451,506 2' Claims; (Cl.-166-55) The present invention may be briefly described as a gun.

perforator and method for perforating the casing in a cased and tubed well in which the tubing is permanently arranged in the casing which comprises, in combination,

an? elongated body member larger in horizontal cross section than the tubing but smaller in horizontal cross section than the casing. The body member is provided with at least one lateral socket or gun barrel and the lateral socket is provided with explosive means for perforating the casing. The body member is also provided with means for detonating the explosive means. A releasable connecting means is connected to the body member for connecting the body member to the lower open end of the tubing string arranged in the casing. The releasable connecting means releases the body member from the lower open end of the tubing after firing the explosive means to provide a full open tubing.

The releasable connecting means allows the body mem-- her with the gun barrels to be disposed at any desired level in the well below the tubing to perforate the casing. Thereafter, the releasable connecting means may be retrieved from the well through the tubing. The explosive means may comprise a bullet and a high explosive charge or the explosive means may be a high explosive shaped charge.

The releasable connecting means may be a retrievablecarrier member connected to the upper end of the body member and may suitably include at least one frangible means, such as a shear pin, and an explosive detonator which serves to break away the body member from the releasable connecting means and drop the body member in the casing while the retrievable carrier member may be' retrieved through the tubing leaving a full open tubing.

The present invention is particularly adapted for use in a well casing having a tubing string permanently arranged with its lower open end above the highest of a series or plurality of hydrocarbon productive strata. Thus the present invention is particularly useful in the so-called permanent well completion method which has found utility in the petroleum industry. This permanent well completion method is one in which the tubing and the wellhead are set in place only once in the life of the well and the completion or remedial work after the initial completion is performed through the tubing with wire line equipment. This method allows the bringing in of wells and workover of wells without requiring the employment of heavy duty lifting and hoisting equipment and also allows the bringing in of wells without killing same eliminating the detrimental efiects of heavy fluid such as drilling mud in the'well which frequently contaminates and plugs perforations made through the casing. in the) formation.

In the permanent well completion method, however, is the practice to lower a tubing gun through the tubing, which is permanently fixed in place, and to penetrate the well with the tubing gun. By virtue. of the limited area. for passage of the tubing gun, it is necessary that the tubing gun be made of relatively small cross-sectional area to pass freely through the tubing. This necessarily" limits the size of the high explosive which is used either to propel a bullet or in the form of a shaped charge to penetrate thecasing and the cement surrounding the casing and. the: formation. This is disadvantageous in that:

the smallness of the explosive. charge limits the penetra tion.

In the presentv invention such disadvantages are eliminated by providing below the lower open end of the tubing a rigid, non-expansible gun perforator having a crosssectional area greater than the cross-sectional area of the tubing but smaller than the cross-sectional area of the casing. After firing the gun perforator, the gun perforator' body is released from below the lower open end of the releasable and retrievabl'e carrier member of sufficient" length to reach the desired level. The carrier member may be only one or two feet in length or may extend toas much as 1000 feet or more below the lower open end of the tubing. The retrievable carrier member may suit-' ably be a tubular member which may be landed in the lower end of the tubing and then retrieved therefrom after the body member has been released therefrom.

The invention will be further illustrated by reference to the drawing in which:

Fig. 1 represents one embodiment;

Fig. 2' shows another arrangement of the present invention; and I Fig. 3 illustrates the gun of Fig. 2' released from the end of the tubing and the well in condition for subsequent operations.

Fig. 4 is a preferred embodiment of the present invention similar to Fig. 1 wherein an elongated carrier is employed';

Fig. 5 illustrates the condition of the well after the perforator gun has been disengaged from the embodiment of Fig. 4;

Fig. 6 shows the retrievement of the carrier body of Figs. 4 and 5;

Fig. 7 shows a detail of the power source of Fig. 4;

Fig. 8 is a modification of the upper end of the carrier y;

Fig. 9 shows a further modificationv of the upper end of the carrier body; and

Fig. 10 is a still further modification of the carrier body.

Referring now to the drawing, in which identical nu'- merals will be employed to designate identical parts, and particularly to Fig. 1, numeral 11 designates a well drilled in the earth in which a casing 12 has been arranged and cemented in place with cement 13.

The tubing 14 has been arranged in the well with the lower open end 15 permanently set above a hydrocarbon productive stratum, zone, formation, interval or sand 16 from which production is to be had. On running the tubing into the well a gun perforator 17 provided with a plurality of gun barrels 18 each having a bullet 19 and an explosive charge 20 arranged therein is connected to the'open end of the tubing by means of a carrier member or body 21 which is connected to the tubing by means of a shoulder 22 landed in a landing nipple 23. It is to Patented Mar. 10,1959

tubing 14. The carrier member or body 21 is provided with a fishing neck 25a and also has an electrical conductor'24 extending the length thereof to'make contact with an electrical contact 25 on neck 25a. typewell known. The carrier body member should have a length sufi'icient to extend from the lower end of the tubing to the level, interval or stratumto be perforated initially.

The gun perforator 17' is connected to the carrier body member 21 by frangible means, such as shear pins 26, and by a disengaging detonator 27. The shear pins 26 and the detonator 27 are connected to a neck 28 of the gun perforator 17. The electrical conductor 24 is connected to the detonator 27 which in turn connects with a detonating cord 29 which may be a Primacord which makes contact with the explosive charge 19 in the gun barrels 18.

Arranged on an electrical conductor cable 30 and suspended therefrom is a power section,31 which may be electrically connected through cable 30 to an electrical source at the earths surface. The power section 31 is arranged in an elongated carrier 33 provided with centhe upper end of the fishing This is an insulated electrical contact of a,

the lower end of tubular carrier member 60 for circulation of fluid prior to disengagement of gun 17 It will be noted that the production interval 61 is one of a plurality of productive intervals, such as 62 and 63, and that the lower open end 15 of the tubing 14 is arranged above the uppermost of the plurality of productive intervals 61, 62 and 63. An electrical conductor 64 extends from the electrical contact point 25 to the disengaging conductor 27 on the lower end of the tubular carrier body 60.

tering springs 34. The power section 31 is provided with a contact point 35. for contact with the electrical contact 25 on the fishing neck 25a,

Referring now to Fig. 2, the tubing 14 has a carrier plug member 40 landed in a landing nipple 23 and sealed therein with seal 41 constructed of any desired deformable material such as rubber to close thelower end of the tubing 14. Seal41 is secured to nipple 23' by any desired means. Connected to the carrier plug by a connection 42 is an elongated body member 43 which contains a plurality of shaped charges 44 of the type well known to the art. The connection 42 in this embodiment is of relatively short length and ordinarily may be used when the tubing 14 is arranged with its lower end 15 just above the formation to be perforated.

The shaped charges are contained in sockets 45 defined by the conical wall members 46. The shaped charges may comprise a high explosive, such a pentolite, tetryl, and the like, such as RDX, nitrocellulose, ammonium nitrate, and the like.

The plug 40 is provided with an electrical conductor 47 which makes contact with an electrical contact 48 on the upper end of the plug40. The electrical conductor 47 connects to a detonator 27, then to a Primacord, such as 49, which, in turn, connects with the shaped charges 44 in the sockets 45. Detonator 27' ignites Primacord 49 but does not sever plug 40 from body member 43.

In Fig. 3 the gun perforator 43 has been fired by firing the explosive charges 44 and the jet perforator and plug 40 have been disengaged from the tubing 14 and dropped into the bottom of the well by application of pressure in tubing 14, as shown. The perforations 50 have been formed by firing the shaped charges 44 through the casing 12, cement 13 and stratum 16. A tubular extension member 51 has then been lowered on a wire line, not shown, and landed in the resilient seal 41 is secured to landing nipple 23 and sealed therein by means of a seal 52, such as a chevron packing, the wire line, not shown, having been disconnected from the fishing neck 53.

Referring now to Figs. 4 to 6, an elongated carrier member 60 has been landed in the landing nipple 23 of the tubing 14 with shoulder 22 resting in the landing nipple 23. The elongated carrier body 60 is a tubular member having a length sufficient to project from the lower open end 15 of the tubing 14 and extend to a selected production interval, such as 61. The tubular carrier member 60 is provided with ports 60a adjacent 31. The power section 31 Connected to the disengaging detonator 27 by means of shear pins 26 is a perforator gun 17 which is similar to the perforator gun 17 of Fig. 1. Like perforator gun 17 of Fig. 1 the gun 17 of Fig. 4 is provided with a plurality of gun barrels 18, each having an explosive charge 20 and a bullet 19 arranged and adapted to be fired through the detonating cord 29 which connects into the electrical conductor 64.

Electrical conductor cable 30 is connected to section is provided with centering springs 34 and a contact point 35 for engaging with the contact point 25. After the perforator gun 17 has formed perforations, such as the disengaging detonator 27 causes the release of the perforator gun 17 from the elongated tubular carrier and drops same to the bottom of the well 11 as shown in Fig. 5 allowing the tubular carrier body 60 to be retrieved from the well or left in the well as desired for further operation, such as cementing as may be desired.

Referring now to Fig. 6, it will be seen that the carrier member 60 has been retrieved from the well and the tubing 14 has a full open passageway for conducting subsequent operations therethrough. I

Referring now to'Fig. 7, it will be seen that a tubing 14 has a landing nipple 23 arranged in its lower end and a tubular carrier body member, such as ranged therein. In this modification of. the invention, a battery-type power source, such as 70, is lowered on a wire line, such as 71, by attaching same to a fishing neck 72. The power source is provided with a plurality of batteries 73 for energizing of the electrical contact'point 35. Like the embodiments of Figs. 1 to 6, the power source 70 is provided with centering springs 34. It is to be noted that the only difference between the embodiments of Figs. 1 to 6 and Fig. 7 is that batteries supply the electrical energy rather than a separate source at the earths surface.

, Referring now to Fig. 8 in which a different type of firing mechanism is provided, tubing 14 has a carrier body 60 arranged therein in landing nipple 23 with the upper end of the body member 60 modified to provide a plate 81 held to the upper end 80 by means of shear pins 82. Connected to the plate 81 is a downwardly projecting member 83 which has a pointed firing pin 84 depending therefrom. Attached to the plate 81 is an elongated member 85 which, in turn, is connected to a packing member 86 provided with swab cups or packing means 87. The packing member 86 has a fishing neck 88 for 1 retrieving same from the tubing 14. Arranged between the packing member 86 and the plate 81 is a biasing means, such as a helical coil spring 89, normally urging the packing means 86 away from the plate 81. Arranged in operative position from the firing pin 84 and spaced away therefrom is a firing cap 90 to which the detonating cord 90a is connected.

Referring now to Fig. 9, the tubing 14 has a carrier body member, such as 100, connected by means of connecting means 101, containing a firing cap 102, to a carrier plug 103 which is arranged in landing nipple 23. The upper end of the carrier plug has a fishing neck 104 through which projects a firing pin 105. The firing pin 105 extends into operative relationship to the firing cap 101 but is spaced away therefrom and normally held in inoperative position by a biasing means or spring 106. Shown in the tubing 14 immediately above the upper end 65, in the formation or interval 61,

60, has been ar- .5 of-the firing pin 105 is a weight-type go-devil 107 which is about to strike the firing pin 105.

In Fig. 10 a different type -cf firing mechanism is shown arranged'in the carrier plug 103. In this embodiment, the firing pin'110 is held in the upper end of the carrier plug by means of a soluble pin 111 which may suitably be constructed of magnesium or caustic. The pin 110 is normally biased toward the firing cap 101 by biasing means, such as spring 112.

The present invention operates in the following manner: It will be noted with respect to Fig. 1 that the perforating gun 17 is suspended by means of a shear pin 26 from the end of the elongated carrier body 21 which, in turn, is supported in a landing nipple 23. Landing nipple 23 may be a permanent installation in the tubing 14. To fire the perforator 17 the power section 31 is lowered on a cable or Wire line 30 until the contact point 35 engages the contact point 25 establishing the circuit through the carrier body 21 and to the disengaging detonator 27. The contact springs 34 complete the circuit from the tubing to the carrier body 21 and to the disengaging detonator 27, which contains an explosive charge sufficient t'o release'the body 21. On firing the bullets 19, the perforator 17 disengages from the body 21 by shearing the shear pins 26 practically instantaneously with the firing of the bullets 19, leaving the carrier body 21 in the lower end of the tubing and allowing the perforating gun '17 to drop to the bottom of the well where it is out of the way of producing operations. (Note that the Primacord burns exceedingly fast so that the explosive charges detonate substantially simultaneously; thus the perforating gun does not drop appreciably before the perforating charges are fired.) p This leaves the lower end of the tubing free and, on pulling the power section 31 from the well, a wire line fishing tool may then be lowered into the. tubing 14 to engage withv the fishing neck 24 and to pull carrier body 21 from the tubing'th'us providing a full open tubing for subsequent producing, workover and servicing operations. All these operations are performed Without moving the tubing 14.

Referring. now to Figs. 2 and 3, a similar operation is performed. The power section or power source 31 is brought into contact with the electrical contact 48 which serves to detonate the shaped charges 45 and to cause same to perforate the casing 12 and cement 13 as well asythe sand 16. After the perforator 43 has been fired, pump pressure is then built up on the tubing 14 to force the plug 40, to which is attached the perforator 43, out the lower end 15 of the tubing thus providing a full open tubing, as shown in Fig. 3, for lowering a tubularextension member 51 down the tubing for subsequent operations such as producing and servicing.

If desirable, the perforators of Figs. 1 to 3 which fall to the bottom of the well may be constructed of aluminum and disintegrated substantially completely by flowing a caustic solution down the tubing 14 in contact with the perforator 17 or 43 to disintegrate same by chemical reaction.

Referring now to Figs. 4 to 6, the tubing 14 has been run into the casing 12 with the carrier body 60 landed in the landing nipple 23 and projecting from the lower end 15 of the tubing 14 a sufiicient distance such that the perforator 17 is positioned opposite the formation 61 or hydrocarbon productive interval which is to be perforated.

It is desirable to lower the tubing 14, to which the tubular carrier 60 is releasably attached, past the interval 61 such that at least a portion of the mud in the well may be circulated out and replaced by a clean liquid. For example the ports 60a may be positioned below interval 61 and mud in the well circulated out by either reverse or normal circulation leaving a clean liquid in the well adjacent interval 61. Thereafter the tubing 14 and carrier 60 will be pulled up in the well to position the perforator gun 17 adjacent the formation or interval 61 for perforating same. It is desirableto fire the perform tor ina clean liquid since otherwise the perforations 65,- when formed, may be plugged from mud in the well. It is to be noted with reference to Figs. 4 through 6 that the tubing 14 and attached perforator gun 17 are permanently set according to the permanent well completion technique after replacing the mud by clear liquid since the circulation step requires manipulation of the tubing 14 as recited supra.

With the perforator gun 17 at the point indicated, the electrical conductor cable 30 is energized to provide energy to the power section 31 which fires the explosive charges 20 in the gun barrels 18 and causes the bullets 19 to perforate the casing 12 and. cement 13 and the formation 61. Immediately after firing the bullet 19, the disengaging detonator 27 is fired (for example, by a slowburning fuse) which detaches the gun perforator 17 and causes it to drop to the bottom of the well as shown in Fig. 5, leaving the tubing 14 and the tubular carrier body 60 to form a passageway which effectively extends the length of the tubing 14. Operations, such as servicing the hydrocarbon productive interval to complete same, may then be conducted through the tubing 14 and the tubular carrier member 60, if desired, or the tubular carrier body member 60 may be retrieved as shown in Fig. 6 and production operations carried on until the hydrocarbon productive interval becomes depleted or uneconomical to produce due to water and/or gas. encroachment. Thereafter a tubular member 51, such as shown in Fig. 3, may be lowered into the well on the end of a wire line, such as 71 as shown in Fig. 7, to establisha flow path from the lower end of the tubing to a selected level in the casing, and the perforations 65 sealed .by introduction of cement shown as nodules 50 (Fig. 3) and 66 (Fig. 6) through the tubular member 51 and, after sealing the perforations 65, circulating out excess fluid cement by flowing a material, such as salt water, down the annulus A and up the tubular member 51 and through the tubing 14 to the earths surface. Other treating fluid operations. may be employed instead of cement as for example in acidizing, hydrofracing and other similar conventional workover operations. After such operations, a wire line tubing gun perforator may be lowered through the tubing 14 and the interval 62 or 63 perforated as may be desired.

In the device of Fig. 7, the battery-type power source, such as 70, is used and lowered on wire line 71. As the contact point 35 engages with the contact point 25, the electrical conductor 64 receives energy and causes the gun perforator, such as 17 (Fig. 1), to be fired and subsequently disengagedfrom the carrier body 60.

In the device of Fig. 8 the firing pin 84 is forced into contact by pumping down against the packer 87 which causes the shear pins 82 to be ruptured. This forces the (member 83 and the firing pin 84 into contact with the firing cap which causes the detonation of the detonator cord 90a and thereafter the firing of the gun 17 and the disengaging detonator 27 as has been described.

The device of Figs. 9 and 10 operate in a similar manner with the exception that in Fig. 9 the go-devil 107 strikes the firing pin which causes same to overcome the spring 106 and then causes the pin 105 to strike the cap 101, firing the detonating cord 90a and subsequently the gun 17 and the disengaging detonator 27. v

The device of Fig. 10 operates in a similar manner by lowering in a dump bailer or the like or by circulating a body of caustic soda to come into contact with the soluble pin 111. As the pin is dissolved by the action of the chemical, the biasing means 112 causes the firing pin 110 to spring into contact with the cap 101 to fire same and also the detonating cord 90a and thereafter the gun 17 and the disengaging detonator 27 to release the perforator, as has been described.

Although several types of connections and firing mechanisms have been described and illustrated, it is to be the drilling mud. This Q cred into f the; well; a la understood that -:otlier connecting means may be employed I I ysuchas the plug 40 whichmay' beforc'ed outof the :';I The, invention'provides a gun perforator larger in I 1 diameter than: :the, tubing for initial; perforation of a i wellbut smaller; in diameter I i 31 present invention; perforates the casing with iapressure 1 difieren tial into thewell bore; I'Ihus the well may be i 2 under :control with a hydrostatic column of fluid; St at 1 5 ing' this otherwise, thewell does not haveto be killed with mud and itis possible to; have a clean fluid; such i 1 as oil orsalt water and the like, in thewell" during the perforating} operations which will: eliminate plugging of 1 ing been completely 1 described and illustrated, what I g 1 wish toclaim as new i and useful and ,to' secure :by Letters Patent is: I

' 1 i i 1. Apparatus for perforating casing in a cased well,

explosive means in said atleast one socket forperforat-f than the casing. Alsothe mounted: on said ca I er LasLi'nFig; 1 maybe dispensed with andfreplaced: bya f "Plugasin-Fig.12,1% I

' i the perforations and the formation :with thesolids from p i I i I I I I ay beac'complished by remow i 1: i ing: the mud prior: to positioning the: gun perforator or I afterward by providing eirc" lating ports in the tubular I i 1 I carriermernber as has been described, Furthermore, the a present invention :has, Wide utility in that movement of {the tubing afteriperforatingfof the well is avoided and 1 f 1 an unobstructed passage; through the tubing is provided:

i I after firing the gun, which is run in onthe tubing in 1 thepresent'invention. I ;1;1 ,1 i r 1, The nature andobjeets of the: present {invention :havii i said apparatus comprising: af tubing adapted to below 1 p I I ding nipple near I the: lower I I end of said tubing including a Shoulder-supporting means;

I a I deformable sealing means in said landing nipple; an

elongated, rigid body' member larger: in; cross;section 1 than the tubing but smaller in cross-section than the cas i ing; at least onelateral socket in: said bodyri.'1ernber;:4;3 5 1 sealingrneans carried by said ignition 1 with the interior wall of the tubing, "said housing being I rriermember, shearpini'rneans con I 1 necting isaid firing pinto: saidhousing above said firing 1 cap, fluid: pressurein said tubing exerted above said ignition means rupturing said I 5 ing said firing pin, againstsaid firingcap andigniting said Primacord; said: retractablei 1 7 a I at adapted to retract into said I 1 i shouldermeans bein'g furth I 1 a givenfluid pressure in 1 i 1' carrier member responsive to the tubingtopermitforcing of said carrier memberout 1 I st said deformable sealingfmeans 1 1 and out of the lower extremity {of the tubing. 1; 1 l2. Apparatus for pejrforating a casing: in a cased I said apparatus comprising; i a i eredinto the well, alanding of said landing nipplepa of the tubing; said i Iandin j porting means; deformab an elongated, I than the tubing I than; the casing; atleast one lat 1: member; explosive: means in said 4 at least; one socket 1 1 7 a carrier: member connected 1 1 twardly biased {retractabler i 1 p I mber; Said shoulder 7 mea s being'adapted toland injsa'idlanding nipple for i; :1 carrier member to said landing i I er ;merrlber; prfliects from the I 1 means: for: detonating said ex 1 f a f ,Primacord connected Eto;said 1' 1 1 I said retractable-shoulder means, being tract into said carriermember roe 1 a); perforating the casing; i to said body member; on 1 shoulder means in said carrier me f 1 releasably' aflixing said nipple so, that said ,carti lower end of the tubing? plosive means; including a explosive means; [further adaptedto re 7 1 sponsiveitoagiven fiuidpressureiin the tubing to permit: 1 1 1 I 9 past said deformable se extremityv of the tubing. 1

: in g, nipple;

ero'ss section Broadwater- -..1 '..,...1 ...1May 28, Church Oct. 8, Anderson Oct. 20, Walker Aug. 15, Muskat et a1 Jan. 10, Huber Nov. 21, Bond et a1 Sept. 15, Kanady Sept. 28, Kanady Apr. 12,

FQREIGN PATENTS Great Britain Apr. 24,

means and sealing, 1

shear: pin; means and driv I 1 1 firing cap, detonating said n; i i 1 i tubing adapted to be low i 1 nipplen'earithelower end I g nipple including shoulder sup-1 1 1 i 1e sealing. means in saidlandg- 1 y 1 irigid bodymember target in I f bnt smaller incrosssection 1 I 1 1 eral socket in said body; 1 1:

f rc is of a arrier m mb r out of saidlanding'nipple I 1 i i sling ma d9mb 1hhwr 1 i ff flReferences Cited in'thefileofthispatent 1 7 1UNI ST TESJPATENTS i i i i I 1907; 1 

